1. Field of the Invention
Embodiments of the present disclosure relate generally to a system, a device and a method for sustained medical infusion of fluids and/or continuous monitoring of body analyte. More particularly, the present disclosure is related to a portable infusion patch-like device securable to the skin that, optionally, can also continuously monitor body analytes. In some embodiments, a multi-component fluid dispensing and/or bodily analytes monitoring device is provided that is powered by a miniature highly efficient energy supply source.
2. Background of Invention
Medical treatment of several illnesses requires continuous drug infusion into various body compartments, such as subcutaneous and intra-venous injections. For example, diabetes mellitus patients require the administration of varying amounts of insulin throughout the day to control their blood glucose levels. In recent years, ambulatory portable insulin infusion pumps have emerged as superior alternatives to multiple daily injections of insulin by syringe. These pumps, which deliver insulin at continuous basal rates as well as in bolus volumes, were developed to liberate patients from repeated self-administered injections, and to enable them to maintain a near-normal daily routine. Other examples of treatments based on the use of infusion pumps are treatments to treat post surgery pain that require relief by medication (e.g., opium derivatives). These drugs may be locally delivered to the subcutaneous tissue surrounding the incision scar to thus avoid systemic side effects of oral or intravenous administered analgesics. Other examples for applications of such pumps include using these pumps with cancer patients that require continuous delivery of chemotherapy medications via an open vein access port.
First generation of portable insulin pumps were “pager like” devices with a reservoir contained within a device housing. A long tube delivered insulin from the pump attached, for example, to a patient's belt to a remote insertion site. The reservoir, delivery tube and the hypodermic cannula were altogether named the “infusion set”. The recommendation for infusion set replacement was every 2-3 days to avoid local infection at the cannula insertion site. However, most diabetes pump users extended this period until reservoir emptying, which sometimes occurred up to 7 days after the initial use. Such devices are disclosed, for example, in U.S. Pat. Nos. 3,631,847, 3,771,694, 4,657,486 and 4,544,369, the contents of all of which are hereby incorporated by reference in their entireties. These devices represent a significant improvement over the use multiple daily injections, but suffer from drawbacks, among which are the devices' relative large size and weight. The main factor contributing to the devices' heaviness and bulk was their use of relatively large driving mechanism and large sized batteries (e.g., of AA-type , or AAA-type) required to meet the high energy demands of the motor, screen, alarms and other components of the devices.
These uncomfortable, bulky devices with long tubes are rejected by the majority of diabetic insulin users because they disturb their regular activities, e.g., sport activities such as swimming. To avoid the tubing limitations, a new concept of a second generation was proposed. The new concept included a remote controlled, skin securable (e.g., adherable) device with a housing having a bottom surface adapted for contact with the patient's skin, with a reservoir contained within the housing, and with an injection needle adapted for fluid communication with the reservoir. These skin-securable devices are designed to be replaced every 2-3 days similarly to the currently available pump infusion sets. However, most patients prefer to extend this period until reservoir emptying. This paradigm was described in U.S. Pat. Nos. 4,498,843, 5,957,895, 6,589,229, 6,740,059, 6,723,072, and 6,485,461, the contents of which are hereby incorporated by reference in their entireties. These second generation skin securable devices have two drawbacks. First, the single piece device has to be disposed of every three (3) days with its all expensive components (electronics, driving mechanism, etc.). Second, a 2nd generation remote controlled skin-securable device is generally heavy and bulky, which is a drawback because the device is directly attached to the patient's skin and remains in place for at least three (3) days. One of the reasons for the large size and heavy weight is the size and number of batteries that supply energy for maintaining a communication link between the skin securable device and the remote control unit, in addition to supplying energy to the energy-consuming components of the devices, such as the motor, display device, alarm, etc.
In U.S. Pat. No. 7,144,384, the contents of which are hereby incorporated by reference in its entirety, a skin adherable device is disclosed. A large portion of the entire volume of this device is occupied by the batteries. In one embodiment, four watch (button) batteries are needed to meet the dispenser energy requirements. The plane of the four button batteries is positioned perpendicularly to the longitudinal axis of the device and consequently the device is relatively thick (18 mm) and bulky. Moreover, because the energy requirements of the device are high, these heavy and bulky batteries last for only three (3) days forcing the user to dispose of the device after three (3) days.
A watch battery or button cell is a small form-factor battery designed for use in wrist watches, pocket calculators, hearing aids, and similar compact portable electronics products. The main advantage of watch batteries is their size, particularly their thickness. Unlike AA or even AAA cylindrical shape batteries, having diameters of at least 10 mm, watch batteries are flat, usually having a thickness of 3-5 mm. A watch battery typically includes a single cell with nominal voltage between 1.5 and 3 volts. Common anode materials include zinc or lithium, and common cathode materials include manganese dioxide, silver oxide, and carbon monofluoride (or copper oxide). The cylindrical outer casing of these types of batteries forms part of the positive (+) terminal. The “C” type 3-V lithium cells and the “S” type 1.5 volt silver oxide cells are the most commonly used watch batteries.
In U.S. patent application Ser. No. 11/397,115, entitled “Systems and methods for sustained medical infusion and devices related thereto” (published as U.S. Publication No. 2007/0106218), and in U.S. provisional application No. 61/123,509, entitled “Systems, devices and methods for fluid delivery”, the contents of which are hereby incorporated by reference in their entireties, a so-called third generation device was described that includes a remote controlled skin adherable dispensing patch having reusable and disposable parts. In some embodiments of these dispensing devices, button batteries residing within the disposable part of a dispensing device are used. Such third generation device described is relatively thin (e.g., a thickness of not more than 15 mm) and meets all energy requirements for the entire usage duration of the device, e.g., more than three days.
The prior art also describes continuous glucose monitors (see, for example, U.S. Pat. Nos. 5,390,671 and 6,143,164, the contents of which are hereby incorporated by reference in their entireties). These devices monitor glucose levels in the subcutaneous compartment of a patient's body. U.S. patent applications Ser. Nos. 11/706,606, 11/989,665 and 11/989,678, the contents of all which are hereby incorporated by reference in their entireties, describe a dual function patch-like fluid dispensing device that dispenses fluids and continuously monitors body analytes (e.g., insulin dispensing and glucose monitoring). In some of the disclosed embodiments of such dual function dispensing device, a closed loop system is described in which insulin was delivered according to certain glucose levels. In some embodiments of such disclosure, the dual function patch is composed of reusable and disposable parts, where, for example, the batteries reside within the disposable part. Similar to the single-piece “stand alone” dispensing device, this dual function device is relatively thin (thickness being not more than 15 mm) and meets all energy requirements for the entire usage duration, e.g., for more than 3 days.